Artificial tooth.



Patented July 13, 1915.

A. VIS.

ARTIFICIAL OTH ARTHUR H. DAVIS, 01 BERLIN, GER...

.anrmicmn room mate.

Specification of Letters Patent.

Patented an t3,19t5.

Application filed June 2c, 1913. Serial no. 774,762.

To all whom it may concern:

. Be it known that I, ARTHUR N. DAVIS, a citizen of the United States of North Amer- 10a, and residing at Berlin,-Germany, have 5 invented certain new and useful Improvemeans of .bridges, plates or crowns,- it has lately been the custom to employ, insteadof the pin-teeth used heretofore, removable teeth having crowns which consist entirely of porcelain and have in their lower side a hole by means of which they can be fastened with cement onto a pin located on the U-shaped bridge clasping the rear portion of the tooth. Even if such teeth have considerably improved the appearance of the wearers teeth, mainly because the entire crown consists of porcelain and the bridge 13 located only at the rear or underside thereof and is therefore invisible, these teeth have for that very'reason a great disadvan- 5 tage in that the provision of the hole necesstates the tooth being comparatively deep,

e., broad, in the direction of the interior of the mouth, so that the wearer of'such teeth is not inconsiderably troubled there-' by. The provision of the hole has simultaneously the disadvantage that, e. 9., in front teeth, which must be made comparatively thin, the resulting wall is very thin and these teeth consequently are often broken. The same defect is attached to the side teeth and to molars, because that thickness of wall which is normally adequate becomes considerably reduced owing to the subsequent grinding which is always requisite, and, if this wall is accidentally subjected to excessive stresses, breakage of the tooth results. Moreover, whenthis known form of tooth is mounted on abridge, the latter also needs to project into the mouth to accommodate the abnormal depth of the tooth. The result is that a deep crevice is formed between the lower surface of the bridge and the upper surface of the wearers gum, because these two surfaces are in-. chned to one another at an acute angle. Such a crevice is objectionable because it favors remnants of food being retained in the mouth.

A primary object of my invention is to obviate all these defects, and to this end I arrange that the tooth to be fastened to the bridge or the like has in its side faces, and preferably also in its lower side, grooves or indentations, into which corresponding lugs on the bridge engage, and thus'firmly and quite securely hold the tooth. By arranging that these side grooves or indentations are somewhat inclined to each other, my improved tooth can be readily withdrawn from the bridge, and, if desired, be replaced by a new one.

Owing to my improved tooth being dea signed as described and in consideration of the. defects of the formerly employed fastening holes, the following advantages .are obtained :Firstly, the tooth can have a smaller depth and need have only that depth which the natural tooth at the corresponding part of the set of teeth has or has had. Secondly, my improved artificial tooth simultaneously forms a compact mass which is in no place disproportionately weak and consequently can be subjected to great stresses without breaking or cracking. Thirdly, that subsequent grinding of the tooth which is usually necessary is less likely to detrimentally weaken the tooth as has usually been the case with known teeth which have holes. Fourthly, when my new tooth is mounted on a bridge, a deep crevice such as that referred to above is not formed on the lower side thereof, because the bridge-does not project so far inwardly.

Two illustrative embodiments of my 111- vention are represented by way of enample in the accompanying drawing, where1n:-

Figure 1 is a side elevation, partly in section, showing a side tooth mounted on a bridge according to my invention; Fig. 2 is a vertical section taken on the line aa in Fig. 1, and Fig. 3 is a horizontal section taken on the line bb in Fig 1. Fig. 4 is a side elevation partly in section, showing a front tooth mounted according to my invention, and Fig. 5 is a rear elevation of the tooth shown in Fig. 4:.

' Referring to the drawing, the improved tooth 1, instead of having the hole employed heretofore, has, at least in its side faces, grooves or indentations 6 and may preferably have in its under side an lndentation 7. The bridge at has corresponding rib-like projections 8 and 9 which fit closely into the grooves or indentations and so securely hold the tooth. In other respects the bridge forms, in a manner known 'in itself, a U-formed support for the rear and I lower portions of the tooth. As Figs. 2 and 5 show, the side grooves or indentations 6 "are somewhat inclined relatively to each tionatelyweak, and consequently is not likely to crack or break when subjected to very severe stresses. Grinding is also quite as little likely to result in the tooth being weakened detrimentally. On the other hand, the new form of the tooth permits a considerable reduction in depth as compared with that of a tooth of the above-mentioned earlier type designed for the same place in the set. Hence it follows that the wall of the bridge can, when required, be made con siderably thicker than it would be in earlier teeth, without the wearer feeling that the mouth is unduly filled.

An important improvement hasbeen effected in my new form of tooth in so far as the bridge makesa comparatively large angle with the gum above the jaw, as will be understood from Figs. 1 and 4, and consequently remnants of food cannot lodge in such places to the same extent as in lier construction of tooth. f

'It is obvious that my improved tooth can equally advantageously be either employed as a crown or mounted on a plate. As before stated, therefore, the tooth tapers to ward the gums like an inverted cone, the top of said tooth being of greater diameter than the portions below it, and the bottom 9 of the bridge ends above the bottom of the tooth. The back of the tooth, therefore, tapers toward the front of the tooth. I claim:

. 1. An artificial tooth having grooves in the sides thereof, said grooves being inclined relatively to one another, said grooves v the. earbeing inclined inwardly to each other in the a support embracing and gripp ng said.

wedge-shaped portion in its lower and posterior portions, said support being connected with adjacent teeth.- 4

3. In combination, an artificial tooth having grooves in its periphery and asupport having lugs to engage said grooves, the bottom'of said support presenting a large angle to the gums, said tooth tapering downwardly and inwardly toward the base thereof.

4:. In combination, an artificial tooth having grooves lIl the periphery thereof, a wedge-shaped portion behind said ooves and tapering toward the front of sai tooth, and a support connected with adjacent teeth for embracing and gripping the'lower and posterior portions of said wedge-shaped portion, the'bottom of said support presenting v 1 a large angle to the gums, said support tapering downwardly said tooth.

5. An artificial tooth having grooves in the periphery thereof, a wedge-shaped portion behind vsaid grooves, and tapering downwardly toward the front of said tooth, and a supportfor embracing and gripping the lower vand posterior portions of'said toward the .front of 8O wedge-shaped portion, the bottom of said 

